Output a Qualified DS array element

A co-worker has asked why he cannot specify a qualified DS array element on an 
O-spec.  I scanned the ILE RPG reference, but did not see anything helpful.  
Can anyone shed some light on this restriction?

Here's a little snippet to explain the issue...

     d Sfy             ds                  likeds(Stats) dim(2)
     
     d Stats           ds                  qualified
     d  Ord                          11  2 inz(*zero)
     d  Lns                          11  2 inz(*zero)
     d  GSls                         11  2 inz(*zero)
     d  NSls                         11  2 inz(*zero)

     o          e            PrintLine      1
     o                                           11 '# Of Orders'
     o                       Sfy(1).ord    j     30
     o                       Sfy(2).ord    j     50

The two elements in Sfy represent current and prior year aggregations.  The 
syntax used here is not valid on V5R3.  He had to define additional fields for 
output and move the valued from the qualified DS array to get his program to 
compile.  Hardly an elegant solution.... 

Can someone tell me where this is documented?

Thanks for any advice..

Eric